<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Db
 * @subpackage Statement
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Db2.php 23775 2011-03-01 17:25:24Z ralph $
 */

/**
 * @see Zend_Db_Statement
 */
require_once 'Zend/Db/Statement.php';

/**
 * Extends for DB2 native adapter.
 *
 * @package    Zend_Db
 * @subpackage Statement
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Db_Statement_Db2 extends Zend_Db_Statement {
	
	/**
	 * Column names.
	 */
	protected $_keys;
	
	/**
	 * Fetched result values.
	 */
	protected $_values;
	
	/**
	 * Prepare a statement handle.
	 *
	 * @param string $sql
	 * @return void
	 * @throws Zend_Db_Statement_Db2_Exception
	 */
	public function _prepare($sql) {
		$connection = $this->_adapter->getConnection ();
		
		// db2_prepare on i5 emits errors, these need to be
		// suppressed so that proper exceptions can be thrown
		$this->_stmt = @db2_prepare ( $connection, $sql );
		
		if (! $this->_stmt) {
			/**
			 * @see Zend_Db_Statement_Db2_Exception
			 */
			require_once 'Zend/Db/Statement/Db2/Exception.php';
			throw new Zend_Db_Statement_Db2_Exception ( db2_stmt_errormsg (), db2_stmt_error () );
		}
	}
	
	/**
	 * Binds a parameter to the specified variable name.
	 *
	 * @param mixed $parameter Name the parameter, either integer or string.
	 * @param mixed $variable  Reference to PHP variable containing the value.
	 * @param mixed $type      OPTIONAL Datatype of SQL parameter.
	 * @param mixed $length    OPTIONAL Length of SQL parameter.
	 * @param mixed $options   OPTIONAL Other options.
	 * @return bool
	 * @throws Zend_Db_Statement_Db2_Exception
	 */
	public function _bindParam($parameter, &$variable, $type = null, $length = null, $options = null) {
		if ($type === null) {
			$type = DB2_PARAM_IN;
		}
		
		if (isset ( $options ['data-type'] )) {
			$datatype = $options ['data-type'];
		} else {
			$datatype = DB2_CHAR;
		}
		
		if (! db2_bind_param ( $this->_stmt, $position, "variable", $type, $datatype )) {
			/**
			 * @see Zend_Db_Statement_Db2_Exception
			 */
			require_once 'Zend/Db/Statement/Db2/Exception.php';
			throw new Zend_Db_Statement_Db2_Exception ( db2_stmt_errormsg (), db2_stmt_error () );
		}
		
		return true;
	}
	
	/**
	 * Closes the cursor, allowing the statement to be executed again.
	 *
	 * @return bool
	 */
	public function closeCursor() {
		if (! $this->_stmt) {
			return false;
		}
		db2_free_stmt ( $this->_stmt );
		$this->_stmt = false;
		return true;
	}
	
	/**
	 * Returns the number of columns in the result set.
	 * Returns null if the statement has no result set metadata.
	 *
	 * @return int The number of columns.
	 */
	public function columnCount() {
		if (! $this->_stmt) {
			return false;
		}
		return db2_num_fields ( $this->_stmt );
	}
	
	/**
	 * Retrieves the error code, if any, associated with the last operation on
	 * the statement handle.
	 *
	 * @return string error code.
	 */
	public function errorCode() {
		if (! $this->_stmt) {
			return false;
		}
		
		$error = db2_stmt_error ();
		if ($error === '') {
			return false;
		}
		
		return $error;
	}
	
	/**
	 * Retrieves an array of error information, if any, associated with the
	 * last operation on the statement handle.
	 *
	 * @return array
	 */
	public function errorInfo() {
		$error = $this->errorCode ();
		if ($error === false) {
			return false;
		}
		
		/*
         * Return three-valued array like PDO.  But DB2 does not distinguish
         * between SQLCODE and native RDBMS error code, so repeat the SQLCODE.
         */
		return array ($error, $error, db2_stmt_errormsg () );
	}
	
	/**
	 * Executes a prepared statement.
	 *
	 * @param array $params OPTIONAL Values to bind to parameter placeholders.
	 * @return bool
	 * @throws Zend_Db_Statement_Db2_Exception
	 */
	public function _execute(array $params = null) {
		if (! $this->_stmt) {
			return false;
		}
		
		$retval = true;
		if ($params !== null) {
			$retval = @db2_execute ( $this->_stmt, $params );
		} else {
			$retval = @db2_execute ( $this->_stmt );
		}
		
		if ($retval === false) {
			/**
			 * @see Zend_Db_Statement_Db2_Exception
			 */
			require_once 'Zend/Db/Statement/Db2/Exception.php';
			throw new Zend_Db_Statement_Db2_Exception ( db2_stmt_errormsg (), db2_stmt_error () );
		}
		
		$this->_keys = array ();
		if ($field_num = $this->columnCount ()) {
			for($i = 0; $i < $field_num; $i ++) {
				$name = db2_field_name ( $this->_stmt, $i );
				$this->_keys [] = $name;
			}
		}
		
		$this->_values = array ();
		if ($this->_keys) {
			$this->_values = array_fill ( 0, count ( $this->_keys ), null );
		}
		
		return $retval;
	}
	
	/**
	 * Fetches a row from the result set.
	 *
	 * @param int $style  OPTIONAL Fetch mode for this fetch operation.
	 * @param int $cursor OPTIONAL Absolute, relative, or other.
	 * @param int $offset OPTIONAL Number for absolute or relative cursors.
	 * @return mixed Array, object, or scalar depending on fetch mode.
	 * @throws Zend_Db_Statement_Db2_Exception
	 */
	public function fetch($style = null, $cursor = null, $offset = null) {
		if (! $this->_stmt) {
			return false;
		}
		
		if ($style === null) {
			$style = $this->_fetchMode;
		}
		
		switch ($style) {
			case Zend_Db::FETCH_NUM :
				$row = db2_fetch_array ( $this->_stmt );
				break;
			case Zend_Db::FETCH_ASSOC :
				$row = db2_fetch_assoc ( $this->_stmt );
				break;
			case Zend_Db::FETCH_BOTH :
				$row = db2_fetch_both ( $this->_stmt );
				break;
			case Zend_Db::FETCH_OBJ :
				$row = db2_fetch_object ( $this->_stmt );
				break;
			case Zend_Db::FETCH_BOUND :
				$row = db2_fetch_both ( $this->_stmt );
				if ($row !== false) {
					return $this->_fetchBound ( $row );
				}
				break;
			default :
				/**
				 * @see Zend_Db_Statement_Db2_Exception
				 */
				require_once 'Zend/Db/Statement/Db2/Exception.php';
				throw new Zend_Db_Statement_Db2_Exception ( "Invalid fetch mode '$style' specified" );
				break;
		}
		
		return $row;
	}
	
	/**
	 * Fetches the next row and returns it as an object.
	 *
	 * @param string $class  OPTIONAL Name of the class to create.
	 * @param array  $config OPTIONAL Constructor arguments for the class.
	 * @return mixed One object instance of the specified class.
	 */
	public function fetchObject($class = 'stdClass', array $config = array()) {
		$obj = $this->fetch ( Zend_Db::FETCH_OBJ );
		return $obj;
	}
	
	/**
	 * Retrieves the next rowset (result set) for a SQL statement that has
	 * multiple result sets.  An example is a stored procedure that returns
	 * the results of multiple queries.
	 *
	 * @return bool
	 * @throws Zend_Db_Statement_Db2_Exception
	 */
	public function nextRowset() {
		/**
		 * @see Zend_Db_Statement_Db2_Exception
		 */
		require_once 'Zend/Db/Statement/Db2/Exception.php';
		throw new Zend_Db_Statement_Db2_Exception ( __FUNCTION__ . '() is not implemented' );
	}
	
	/**
	 * Returns the number of rows affected by the execution of the
	 * last INSERT, DELETE, or UPDATE statement executed by this
	 * statement object.
	 *
	 * @return int     The number of rows affected.
	 */
	public function rowCount() {
		if (! $this->_stmt) {
			return false;
		}
		
		$num = @db2_num_rows ( $this->_stmt );
		
		if ($num === false) {
			return 0;
		}
		
		return $num;
	}
	
	/**
	 * Returns an array containing all of the result set rows.
	 *
	 * @param int $style OPTIONAL Fetch mode.
	 * @param int $col   OPTIONAL Column number, if fetch mode is by column.
	 * @return array Collection of rows, each in a format by the fetch mode.
	 *
	 * Behaves like parent, but if limit()
	 * is used, the final result removes the extra column
	 * 'zend_db_rownum'
	 */
	public function fetchAll($style = null, $col = null) {
		$data = parent::fetchAll ( $style, $col );
		$results = array ();
		$remove = $this->_adapter->foldCase ( 'ZEND_DB_ROWNUM' );
		
		foreach ( $data as $row ) {
			if (is_array ( $row ) && array_key_exists ( $remove, $row )) {
				unset ( $row [$remove] );
			}
			$results [] = $row;
		}
		return $results;
	}
}
